General Note: "F" temper applies to products which acquire some temper from fabricating processes. 1. AASHTO Designation M 193. 2. Chemical composition only. 3. Compatible stainless or coated steel nuts and washers shall be used. Aluminum not permitted for anchor bolts. 4. Alloy 2024-T4 shall have an anodic coating of .00020′′ (5.08 μm) minimum thickness with dichromate or boiling water seal. 6. Permitted as an alternate material for minor bolts. 7. For use with aluminum bolts and screws. Aluminum not permitted for anchor bolt nuts and washers. 8. Recommended specifications is B211, but 2221 acceptable as an alternate. 9. In general, T4 temper is applicable to thicknesses of 4 inch (6.350 mm) and over, and T3 is applicable to lesser thicknesses. 10. Recommended specification is B316, but B221 acceptable as an alternate. 11. For rivets to be cold-driven. 12. For rivets to be driven at temperatures of 990° F. (532 t° c) to 1050° F (566 t° c). 717.18. Elastomeric Compression Joint Seals. Elastomeric compression joint seals shall conform to AASHTO M 220. 717.19. Metal bin type crib walls. The galvanized sheets shall conform to the applicable requirements of AASHTO M 218. The various members shall be fabricated from specified metal of the thickness shown in the plans. Section 718 REFLECTIVE SHEETING 718.01 Testing Procedures. (a) Reflective intensity shall be determined as follows. (1) Apparatus Arrangement for the reflective intensity test shall be as shown in Figure 1 in subsection 633.06(b). A light projector having a maximum lens diameter of 1 inch (25.4 mm) and capable of projecting a uniform light shall be used to illuminate the sample. The light falling on the sample shall have a color temperature of 2856K (equivalent to CIE Standard Source A). The light reflected from the test surface shall be measured with a photoelectric receiver whose response has been corrected for the color sensitivity of the average photopic human eye. The dimensions of the active area or the receiver shall be such that no point on the perimeter is more than one-half inch (12.7 mm) from the center. Samples shall be mounted on a flat, black test surface not less than 3 feet (914 mm) square which, when tested without any sample, shall give no appreciable reading. The sample shall be located 50 feet (15.24 m) plus or minus 2 inches (102 mm) from the projector lens and the receiver. The maximum effective area of the test sample shall be 1 square foot (.093 m2). The maximum dimension of the test sample shall be not greater than 1.5 times the minimum dimension. (2) Test Procedure Measure the distance from the projector to the specimen, the area of the test surface, and the illumination incident on the test surface. Measure the illumination incident on the receiver due to reflection from the test surface at each angle of incidence for each angle of divergence. The angles of incidence shall be as required in the applicable reflectivity table. The angles of divergence shall be 0.2 and 0.5 degrees. The illumination incident on the test surface and the receiver shall be measured in the same units. Compute the reflective intensity, R, from the following equation: R = E, (d2) Where: R = Reflective intensity. E, = Illumination incident upon the receiver. Es d Α = Illumination incident upon a plane perpendicular to the incidence ray at the specimen position, measured in the same units as E.. = Distance in feet from the specimen to the projector. Area in square feet of the test surface. = The brightness of the reflective sheeting when totally wet, shall not be less than 90 percent of the dry values in Table III or IV of subsection 633.06(d). Wet performance measurements shall be made on weathered sheeting in accordance with the standard rainfall test specified below: (b) Reflective Intensity During Rainfall The reflective intensity under simulated rainfall conditions (wet performance) shall be determined as follows using the water nozzle and test setup shown in Figure 2. Place the test panels on which the sheeting has been applied in an upright position 6 inches (152 mm) below and 4 inches (102 mm) in front of the water nozzle as shown in Figure 2, of subsection 633.06(b). Apply sufficient water pressure so that the upper surface of the spray envelope strikes the top of the specimen. With water falling on the specimen, determine the reflective intensity, at angles of 0.2° divergence and minus 4° incidence only, as specified above, except that the measurement shall be made on each specimen and the reflective intensity during rainfall shall be the average of the three determinations. (c) Adhesion Test-Subject two 2-inch (50.8 mm) by 6-inch (152 mm) pieces of the reflective material to a temperature of 160° F (66 t°c) and a pressure of 2.5 pounds per square inch (17 kPa) for 4 hours. Bring the materials to equilibrium at standard conditions and cut 1-inch (25.4 mm) by 6-inch (152 mm) adhesion specimen from each piece and remove the liner by hand without the use of water or other solvents. During removal of the liner, it shall be noted whether any liner breaks or tears or removes any adhesive from the backing. Apply 4 inches (102 mm) of one end of each specimen to a test panel. Suspend the panels in a horizontal position with the specimen facing downward. Attach a 14 pound (0.79 kg) weight to the free end of each specimen and allow it to hand free at an angle of 90° to the panel surface for 5 minutes. At the end of the 5 minute period, check the distance of peeling. Failure of any one specimen shall constitute failure of the test. (d) Colorfastness One of the specimens prepared and subjected to accelerated weathering specified in 633.06(j) shall be used to test for colorfastness. Wet out the specimen with a mild detergent and water solution and compare it visually with a similarly treated unexposed specimen under natural (North sky) daylight or artificial daylight having a color temperature of 7500 K. The colorfastness shall be evaluated as follows: Excellent-No appreciable change in color Good-Perceptible but no appreciable change in color |